After inspecting the elements on your page, the input text does not show up because the font-size is 0. I did not have to
Can you try adding this to your theme (you can do a theme override
here
or just temporarily add it to the default theme that you're using)?
.sclogin .input-append {
font-size: 16px;
}
Let me know how it goes and we'll have to test further before adding it to the theme for the next release.
-Melissa